package com.ctgu.cn;

public class Sum {
    public int Add(int n, int m)
    {
        assert n >= 1 && n <= 99;
        assert m >= 1 && m <= 99;
        assert (n+m)>=0 && (n+m)<=99;
        return n+m;
    }
    public int Subtraction(int n, int m)
    {
        assert n >= 1 && n <= 99;
        assert m >= 1 && m <= 99;
        assert (n-m)>=0 && (n-m)<=99;
        return n-m;
    }

}
